Electronic mail remains one of the most popular Internet applications, comparable with online searching. According to industry estimates, there have been about 3.3 billion email accounts by 2012 used by approximately 2 billion users and expected to grow to 4.3 billion accounts by the end of 2016. Over 92% of the adult US population has been using email and 66% of those email users do so as part of their typical day. In a broad picture, email viewing and sending is split between three large platforms: desktop, web, and mobile. Mobile email is quickly evolving into a dominant communication platform. In mid-2011, desktop platforms were prevailing with the split 53% desktop, 29% web, 18% mobile. By February 2012, the three platforms have converged and had approximately equal market share; starting in April 2012, mobile email has overtaken other platforms, with 38% of emails opened on smartphones, tablets and other mobile devices. According to some estimates, within a couple years, mobile email viewing will account for more than 50% of the overall volume.
Email usage on mobile devices is different from desktop and web mail in many respects. While viewing and navigating email messages on smartphones and tablets with a respectable screen size is, for the most part, almost as easy and convenient as on the desktop, responding to emails on devices with on-screen keyboards can be a difficult and tiring job, especially when users are on the go. This puts a strain on some of the most active users of mobile email: managers, journalists and other categories of workers who receive hundreds or even thousands of messages daily and need to respond quickly. Some of the challenges of responding to an email message on a mobile device include: separating fragments of the original text from the rest of mail for commenting; typing comments and edits on soft keyboards; text formatting; adding annotations; identifying annotated materials as part of the original documents, etc. Additionally, existing techniques for transmitting rich content via email significantly limits efficient response. For example, when an email includes attachments opened for editing and markup in non-email applications, the attachments may lack routing information which would allow automatic sending of edited and annotated fragments of the attachment to all or some recipients directly from the authoring application that has opened the attachment. This may cause additional work of saving annotated fragments of rich content and re-attaching the fragments to reply emails, which complicates the workflow and presents additional challenges to both the author/sender and the recipients.
Accordingly, it is desirable to develop a mechanism for fast and seamless email reply on mobile devices with adequate routing of rich content and its annotated fragments.